For someone so young who's neither a power hitter or a pitcher, the Cubs' commitment was impressive. They didn't have to rush to judgment on Castro's net worth, knowing he wouldn't have become a free agent 2016 and still has some learning to do.

But by making Castro a mega-millionaire at 22, the Cubs are banking on Castro becoming a great player who fans will pay to watch, not just a decent singles hitter with a strong arm and an attention span in need of attention.

Castro played in all 162 games this year, starting all but one. He finished seventh in the National League in hits (183) and second in triples (12). Eventually settling down in the order to the No. 5 spot, after stints at Nos. 2 and 3, Castro's home run total went up from 10 to 14, his RBIs zoomed from 66 to 78 and his stolen bases improved from 22 to 25.

Meanwhile, his average dropped from .307 to .283, the first time in Castro's three seasons he finished below .300. He had to finish strong to make it above .280, batting .306 (64-for-209) over the final 52 games after Aug. 8, basically coinciding with the news he was receiving a long-term extension.

No one seems too concerned about Castro's hitting. He should get back to the .300 range if he stays in one spot in the lineup. It's the fielding and concentration lapses that are worrisome.

Castro's 27 errors at short led the majors again; only two other shortstops, Alcides Escobar and Asdrubal Cabrera, had as many as 19. But only two other players, Jose Reyes and JJ Hardy, played more innings at short than Castro, and only Hardy finished with more assists than him.

Manager Dale Sveum pointed out that Castro's accuracy improved, along with his work around second base and turning double plays. But on the last road trip of the season, Sveum, a former shortstop, referred to Castro as a "grass hugger" -- someone who relies too much on his strong arm.

"They don't want to leave that cut of the grass because their arms are so strong," Sveum said. "They don't want to risk gaining ground on a ball. It's not charging a ball, it's gaining and you end up gaining three or four yards on ground balls and angles of balls and things like that. There is no doubt he's still one of those guys who wants to rely on his arm."

Castro also forgets who's running sometimes, not realizing the player's speed, or lack thereof, when making plays. He committed a poor throwing error in Pittsburgh in September on a wild throw with slow-running catcher Rod Barajas running.

"Castro is a heck of a player," starter Jeff Samardzija said afterward. "When he's into the game and he's paying attention to what's going on there are not too many guys out there better."

Samardzija went on to say he loves Castro, as do the rest of his teammates. But the "focus" issue won't go away until he proves he's always paying attention, and that's something you can't really teach.

"There is a lot of it you don't work on," Sveum said. "You just have to be aware of it and play and concentrate to have the awareness of what's going on."

Castro's brain cramp in San Francisco in May, when he forgot how many outs there were, became a defining moment in his relationship with Sveum. After threatening to sit Castro, Sveum changed his mind and gave him a mild chewing out. Castro, who unfairly was singled out at times by former manager Mike Quade, felt like Sveum had his back. He appeared to be into the game almost every pitch the rest of the season.

Castro was the only prominent player who blew off the media the final home game of the season, but he always has been accountable after gaffes. He wants to be the Man and has a good work ethic to help him mature into the role.

"Yeah I'm the face of the franchise," he said. "But it's not like that's something that's going to change me. I'm not going to stop playing hard or stop working hard."